1. Field of the Invention
A nuclear radiation detector of alpha particles, beta particles, gamma rays, X rays and neutrons using the electrical impedance measurements of an interdigitated electrode. The detector is best used to monitor the radiation from cargo containers or for personnel radiation monitoring to determine that radiation doses exceeded a predetermined radiation dose threshold.
The present invention relates to a radiation-warning detector that provides a rapid warning of radiation coming from cargo containers or a rapid warning that personnel have been exposed to radiation in excess of predetermined doses.
2. Description of Prior Art
An immediate response, simple to use, inexpensive radiation-warning detector is needed to monitor alpha particles, beta particles, gamma rays, X rays, neutrons, and/or light using impedance measurements from an interdigitated electrode.
U.S. Pat. No. 4,641,037, Feb. 3, 1987, describes a detector for detecting neutrons comprised of a layer of conductive polymer sandwiched between electrodes. It is hypothesized that the interaction between a neutron and the conductive organic polymer results in the displacement of protons due to the relatively large cross-section of hydrogen atoms for fast neutrons. The resultant measurable change in the properties of the polymer, most notably the electrical conductivity, can be directly measured, preferably electronically, thereby providing a qualitative and/or quantitative assessment of the neutron flux. This prior art is deficient with respect to the present invention in that this detector monitors only neutron radiation using a conductive organic polymer.
U.S. Pat. No. 6,764,583 B2, Jul. 20, 2004, describes the use of resistance (impedance) measurements to detect the presence of pathogens trapped in an electric field. The apparatus involves interdigitated electrodes located on the inner surface of a fluidic channel through which a sample is passed and pathogens are trapped by the dielectrophoretic force. By determining the impedance change, the amount of trapped pathogen can be determined. This prior art is deficient with respect to the present invention in that this detector detects pathogens.
U.S. Pat. No. 4,366,235, Dec. 28, 1982, describes a photosensitive element comprising a support carrying photosensitive silver halide grains in a substantially predetermined spaced array and methods of forming such photosensitive elements. This prior art is deficient with respect to the present invention in that this detector describes a silver-halide photosensitive detector that detects light.
All of the above patents are deficient with respect to the present invention in that they do not address the conversion of silver halide by alpha particles, beta particles, gamma radiation, X rays, neutrons or light to silver and the measurement of resistance (impedance) of silver halide to detect nuclear radiation or light.